The raw food diet, often called raw foodism or raw veganism, is composed of mostly or completely raw and unprocessed foods.

A food is considered raw if it has never been heated over 104–118°F (40–48°C). It should also not be refined, pasteurized, treated with pesticides or otherwise processed in any way.

Instead, the diet allows several alternative preparation methods, such as juicing, blending, dehydrating, soaking and sprouting.

Similar to veganism, the raw food diet is usually plant-based, being made up mostly of fruits, vegetables, nuts and seeds.

While most raw food diets are completely plant-based, some people also consume raw eggs and dairy. Less commonly, raw fish and meat may be included as well.

Additionally, taking supplements is typically discouraged on the raw food diet. Proponents often claim that the diet will give you all the nutrients you need.

Supporters also believe that cooking foods is harmful to human health because it destroys the natural enzymes in foods, reduces their nutrient content and reduces the "life force" that they believe to exist in all raw or "living" foods.

People follow the raw food diet for the benefits they believe it has, including weight loss, improved vitality, increased energy, improvement to chronic diseases, improved overall health and a reduced impact on the environment.

Summary: The raw food diet is made up mostly of foods that have not been processed or heated over a certain temperature.

However, like many of the core beliefs behind the raw food diet, this idea is not backed by science.

In fact, research shows that both cooked and raw foods have health benefits.

One of the main reasons the raw food diet discourages cooking is because of the belief that cooking destroys the natural enzymes in foods. The diet's advocates believe that these enzymes are vital to human health and digestion.

High heat does cause most enzymes to denature — that is, to unravel or change shape. However, many enzymes denature in the acidic environment of the stomach anyway (1, 2).

In fact, the body already produces its own enzymes to facilitate chemical processes including digestion and energy production (3).

Another core belief behind the raw food diet is that cooking destroys the nutrient content of foods.

However, cooking actually increases the availability of other nutrients and antioxidants, such as lycopene and beta-carotene (6, 7, 8).

Cooking also helps inactivate or destroy some harmful compounds in food. For example, cooking grains and legumes reduces lectins and phytic acid. In large quantities, these can block your body from absorbing minerals (9, 10).

A raw food diet has some positive points. Mainly, it is very high in fresh fruits and vegetables. It also incorporates other foods that are high in nutrients and fiber.

To its credit, a raw food diet limits the intake of foods known to contribute to poor health if you eat them in excess, such as processed junk foods and added sugar.

Additionally, a raw food diet nearly guarantees weight loss because it is low in calories. Yet despite this, there are also many cons to a raw food diet.

When someone switches from a mostly cooked diet to a mostly raw diet, their calorie intake is likely to decrease dramatically. Some people may not find it possible to eat enough raw food to meet their daily calorie needs (12, 13).

This is partially because fruits and vegetables, though healthy, simply don't provide enough calories or protein to make up the majority of the diet.

Additionally, cooking increases the digestibility of foods, making it easier for your body to get calories and nutrients from them. In some cases, your body gets significantly fewer calories from a food if it's raw (14, 15).

Like most of the beliefs behind the raw food diet, many of the supposed health benefits are not supported by evidence.

Some studies have found the raw food diet to have positive health effects, but much of the research has found it has negative effects.

One study of people following a raw food diet found that it lowered blood cholesterol and triglyceride levels. However, it also lowered "healthy" HDL cholesterol levels and led to a vitamin-B12 deficiency for many (16).

Another study found that people following a raw diet over long periods of time had an increased risk of tooth erosion (13).

Nevertheless, studies have consistently found that the raw food diet is associated with having less body fat.

One study of participants following a raw diet long-term found that it was associated with large losses of body fat (12).

Men lost an average of 21.8 pounds (9.9 kg) after switching to a raw diet and women lost an average of 26.4 pounds (12 kg). However, 15% of men and 25% of women in the study were also underweight.

Additionally, 70% of women on the diet experienced irregularities in their menstrual cycle. And nearly one-third of women developed amenorrhea, meaning they stopping menstruating, which can be a consequence of low body weight.

Another small study found that people following a raw vegan diet had significantly lower calorie intake and body fat than those who weren't following the diet. Nonetheless, they also had low protein, calcium and vitamin D intakes (13).

The same study found that participants following a raw vegan diet had low bone mass, potentially due to low calorie and protein intake (13).

Overall, following a raw food diet may lead to weight loss or even improve some markers of health, such as blood lipids. But despite this, the significant risk of negative health effects outweighs the potential benefits of this diet.

Summary: Evidence shows that raw food diets are associated with losing body fat. However, they are also associated with serious negative health consequences and the negatives outweigh the positives.

Day Seven

In the short-term, the raw food diet is not likely to pose major health concerns.

However, you may develop problems if you follow the diet long-term.

A mostly raw diet makes it difficult to get enough calories, protein and certain vitamins and minerals.

Some people may not be able to get enough calories from this diet. The evidence also shows that the larger the proportion of raw food in your diet, the higher the risk of negative effects (12).

Unless you take supplements, you may develop problems from nutrient inadequacies over time as your body's vitamin and mineral stores are used up. Vitamin B12 and vitamin D are particularly hard to get in raw vegan diets.

However, even nutrition supplements cannot make up for a lack of calories and protein in the diet.

Additionally, the risk of being exposed to a foodborne illness is increased when you consume foods raw (17).

This is especially true if raw dairy, eggs or meat are part of your diet. Nutrition experts always recommend that people only eat these when they're fully cooked or pasteurized (11, 17).

Lastly, a raw food diet can be challenging to keep up for several reasons.

For starters, food choices are very limited and avoiding cooked foods makes it difficult to go out to eat or to eat with friends.

Avoiding cooked foods also means that food preparation methods are very limited, so a raw food diet can get boring. Many people also find eating only cold foods to be undesirable.

Lastly, it can be expensive to buy so much fresh, organic produce, not to mention time consuming to plan and prepare.

Summary: The raw food diet is probably not harmful in the short-term, but you may experience negative effects if you follow it in the long-term.